抄録
A nitrate-reducing bacterium was isolated from a hot spring and identified as Bacillus licheniformis. This strain was found to accumulate NO-2 in the medium even in the presence of NH+4 by shaking culture when FeSO4 was added to the medium. The NO-2 accumulation was due to nitrate reductase activity, and the same accumulation was also recognized in some other bacteria. Since the nitrate reduction had no marked effect on the cell growth, it is possible that this nitrate reduction may not be involved in either an assimilatory or a dissimilatory one like those hitherto reported.
